Research on the Effect of Near-Field Plates to Electromagnetic Field

2018 ◽  
pp. 1025-1032
Author(s):  
Xiu Zhang ◽  
Zhihan Zhang
Keyword(s):  
Electromagnetic Field ◽  
Near Field

Near-field mapping of the electromagnetic field in confined photon geometries

2002 ◽  
Vol 66 (11) ◽  
Author(s):  
V. Zhuk ◽  
D.V. Regelman ◽  
D. Gershoni ◽  
M. Bayer ◽  
J.P. Reithmaier ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Near Field ◽  
Field Mapping

scholarly journals ВОССТАНОВЛЕНИЕ КОГЕРЕНТНЫХ ИЗОБРАЖЕНИЙ ПОВЕРХНОСТЕЙ В ЗОНЕ ФРЕНЕЛЯ МЕТОДАМИ МНОГОКАНАЛЬНОЙ ОБРАБОТКИ СИГНАЛОВ

2018 ◽  
pp. 97-102
Author(s):  
Валерий Константинович Волосюк ◽  
Семён Сергеевич Жила ◽  
Глеб Сергеевич Черепнин ◽  
Эдуард Алексеевич Цернэ
Keyword(s):  
Electromagnetic Field ◽  
Phase Distribution ◽  
Near Field ◽  
Delta Function ◽  
Basic Function ◽  
Ambiguity Function ◽  
Good Resolution ◽  
Fresnel Region ◽  
Coherent Image ◽  
Multichannel Signal Processing

The generalized structure of the electromagnetic field in the registration area is considered in the case of the solution of problems of remote sensing of the underlying surfaces. Examples of the existing radar and optical coherent devices are given. Analytical expressions for the electromagnetic field in the reception area when sounding is carried out in a near-field Fresnel region, in the assumption that the size of the field of registration and radiation is considerably less than a distance between them, are concretized. It is shown the main operations that are necessary for the recovery of coherent images in a near-field Fresnel region by the methods of multichannel signal processing. Research shows that as the amplitude-phase distribution of the registration field is necessary to choose the classical basic function of Fresnel transformation with the reversed sign in the exponent power. Formally, in an infinite range, the Fresnel transform is invertible, i.e. in the ideal case, the function can be completely restored. However physically to Fresnel's region satisfies area with finite sizes. From the analysis of the obtained operations over the received field, it follows that the radar or optical system forms an estimate of the coherent image in the form of a convolution of a true image of the underlying surface with an ambiguity function. Generally, this function contains two multipliers, one of which determines the resolution of recovery of the coherent image. In that specific case, when the linear sizes of the field of registration go to infinity, ambiguity function takes a form of delta function and the required image can be restored without distortions. It is offered to determine resolution by the width between first zeros of ambiguity function. For rectangular area ambiguity function has the form of two sinc functions which width is directly proportional to wavelength, to the height of sounding and is inversely proportional to the linear sizes of receiving area on the corresponding coordinates. Finally, it is mentioned that for the higher-quality coherent imaging with good resolution by the same receiving area it is necessary to perform scanning and movement in space

Study of electromagnetic field stress impact on SiGe heterojunction bipolar transistor performance

2009 ◽  
Vol 1 (6) ◽  
pp. 475-482 ◽  
Author(s):  
Ali Alaeddine ◽  
Moncef Kadi ◽  
Kaouther Daoud ◽  
Hichame Maanane ◽  
Philippe Eudeline
Keyword(s):  
Electromagnetic Field ◽  
Near Field ◽  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
Scattering Parameters ◽  
Hot Carrier ◽  
Base Current ◽  
Stress Effects ◽  
Device Reliability ◽  
Strip Lines

This paper deals with the various aspects of electromagnetic field impact modeling on the SiGe heterojunction bipolar transistor (HBT) device for microwave applications. This study differs from conventional HBT device reliability research associated with other stresses. The originality of this study comes from the generation of a localized electromagnetic field using the near-field bench. A coupling phenomenon between the electromagnetic field and the micro-strip lines connecting the transistor are evaluated by electromagnetic and electrical simulations. After stress, the input and the transmission scattering parameters are affected. This is primarily due to the deviation of the input impedance and the reduction of the transconductance, respectively. The stress effects have been related to a base current degradation. This degradation is due to a hot carrier introducing generation/recombination trap centers at the Si/SiO2 interface of the emitter–base spacer oxide, which leads to an excess recombination base current.

scholarly journals Validation of numerical methods for electromagnetic dosimetry through near-field measurements

ACTA IMEKO ◽  
2015 ◽  
Vol 4 (1) ◽  
pp. 90 ◽  
Author(s):  
Domenico Giordano ◽  
Luca Zilberti ◽  
Michele Borsero ◽  
Roberto Forastiere ◽  
Wencui Wang
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Field ◽  
Electromagnetic Field ◽  
Boundary Element Method ◽  
Near Field ◽  
Larmor Frequency ◽  
Field Measurements ◽  
Magnetic Element ◽  
Resonance Imaging ◽  
Set Up

This paper describes the arrangement of a first experimental set-up which allows the comparison between the measurement of the electromagnetic field quantities induced inside a simple cylindrical phantom and the same quantities estimated numerically through a boundary element method. The reliability of the numerical method has been tested at 64 MHz, the Larmor frequency associated to the magnetic resonance imaging devices with an isocenter magnetic field of 1.5 T. To assess its robustness, the comparison is also performed by introducing, inside the phantom, a metallic non magnetic element, which roughly simulates a medical implant.

Physics-augmented deep learning for high-speed electromagnetic simulation and optimization

2021 ◽  
Author(s):  
Mingkun Chen ◽  
Robert Lupoiu ◽  
Chenkai Mao ◽  
Der-Han Huang ◽  
Jiaqi Jiang ◽  
...  
Keyword(s):  
Neural Network ◽  
Electromagnetic Field ◽  
Electric Fields ◽  
High Speed ◽  
Near Field ◽  
Physical Constraints ◽  
Simulation And Optimization ◽  
Field Distributions ◽  
The Neural Network ◽  
Nanostructure Arrays

Abstract The calculation of electromagnetic field distributions within structured media is central to the optimization and validation of photonic devices. We introduce WaveY-Net, a hybrid data- and physics-augmented convolutional neural network that can predict electromagnetic field distributions with ultra fast speeds and high accuracy for entire classes of dielectric photonic structures. This accuracy is achieved by training the neural network to learn only the magnetic near-field distributions of a system and to use a discrete formalism of Maxwell's equations in two ways: as physical constraints in the loss function and as a means to calculate the electric fields from the magnetic fields. As a model system, we construct a surrogate simulator for periodic silicon nanostructure arrays and show that the high speed simulator can be directly and effectively used in the local and global freeform optimization of metagratings. We anticipate that physics-augmented networks will serve as a viable Maxwell simulator replacement for many classes of photonic systems, transforming the way they are designed.

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